Jump to content
SAU Community

Recommended Posts

its allways good to have a catch can. its a must have IMHO

Also looks like twin fuel rails mmmm must be a nice car.

Noob question with the return form the back of the head would you still need a catch can.

Brad

Catch can is a bit general term to use..

catch cans are there for engine failures type issues so the oil is caught in that rather than sprayed all over the road/track .. this is a must have in every form of racing i've been involved with.

oil air separators that can do the above job aswell are for removing the oil vapour from the air leaving the head. and not re-introducing it into the combustion process.

I'm looking into options for building a baffled/winged sump on an R32 GTR. In determining dimensions, is it simply a matter of figuring out how wide and deep you can make the wings and then plumbing the pickup accordingly? Does anyone have dimensions or pics of their set up that we could see?

Cheers

  • 1 month later...

Ok im reviving this one for a question

what about using an Accusump type of system to help aleviate the starvation problem? ( www.accusump.com )

but then what about too much oil in the head? my engine is assembled and i dont want to disassemble it to drill out the return or to ADD a return.

Oil supply.... oil drain...

In our N1 car , it has an interesting swinging oil pickup. Cool Nismo piece. Seems to work well. Has a stock sump, stock baffleing - kinda and a swinging oil pickup. I posted some photos of it on gtr.co.uk.

Now if the oil level is in the normal range, the oil pressure will flucuate enough to get me a little afraid of it. I run it at the high mark, and under hard braking it goes down, but not enough for me to worry about any more.

We see about 1.6 g's peak cornering. R34 N1 on 305 Toyo RA1's all around.

The N1 motor doesnt even use an N1 oil pump, they run a Nismo pump. Interesting little thing.

The Tomei oil restrictor is smaller than the N1 restrictor. Stock being 2.0 mm , N1 being 1.5 mm , and Tomei is 1.2 mm.

In the N1 motor , they moved the cam baffle plates to the rear most cam caps. There is also a unique baffle plate in the valve cover.

For catch cans, there are two. A small one that collects and returns to the sump, and a larger one that is about what you see on most street cars.

I have run an Accusump in a GT-R. I never got around to some before and after datalogs of oil pressure though. The car didn't blow up out on the track, so I will assume it works out ok.

Edited by tyndago
Ok im reviving this one for a question

what about using an Accusump type of system to help aleviate the starvation problem? ( www.accusump.com )

but then what about too much oil in the head? my engine is assembled and i dont want to disassemble it to drill out the return or to ADD a return.

Bad luck/timing, disassemble it and do it properly.

:P cheers :D

i was looking into the idea of the swinging pickup but that idea was shot to complete hell but i would like to know more about your setup and how long/how well it has worked out for you.

i run a rb20det rwd so the rear end will step out before i pull some obcene g's in the car, well least my car.

Oil supply.... oil drain...

In our N1 car , it has an interesting swinging oil pickup. Cool Nismo piece. Seems to work well. Has a stock sump, stock baffleing - kinda and a swinging oil pickup. I posted some photos of it on gtr.co.uk.

Ok im reviving this one for a question

what about using an Accusump type of system to help aleviate the starvation problem? ( www.accusump.com )

but then what about too much oil in the head? my engine is assembled and i dont want to disassemble it to drill out the return or to ADD a return.

The oil return is an easy thing to do even if the motor is assembled, provided it is out of the car. Pop the welsh plug out, drill and tap a new one with a 1/4 BSP thread and put a 90 elbow fitting in. If you drill closer to the edge of the welsh plug and install it near the top, you won't foul the metal lines that cross the back of the head.

The other side is to the sump, same scenario, but use a straight fitting.

  • 2 weeks later...
stuff oil control, I want to know how you pulled 1.6g in a full weight gtr on road tyres?

Who said it was full weight ? 1.6 G's while cornering, on a circuit, honestly isn't that impressive. OK for a street race car, not good for a race car. R34 Racecar

The swinging oil pickup is made by Nismo. Its fitted to the Super Taikyu spec motors. Seems to work out alright.

Hey guys just a quick Q for sk When you say drill out the oil returns what size can i drill them to in the head and block

Thanks heaps for all the info you guys have put up it has made my 25/30 project so much easier

The oil return is an easy thing to do even if the motor is assembled, provided it is out of the car. Pop the welsh plug out, drill and tap a new one with a 1/4 BSP thread and put a 90 elbow fitting in. If you drill closer to the edge of the welsh plug and install it near the top, you won't foul the metal lines that cross the back of the head.

The other side is to the sump, same scenario, but use a straight fitting.

1/4 BSP is a bit small for a gravity oil return, about 12mm ID seems to be common

  • 1 month later...

Has anybody tryed venting the sump to atmoshpere/catch can to prevent the pressure build up within the crank.

My thoughts are that with sustained high rpm/load the crankcase is pressurising causing the oil not to drain back to the sump. The oil galleries are below the level of oil which means if the sump is pressurised there is no way for oil to drain back. This is why the mod to drain the back of the head via the welch plug on the rear will work as is it more to do with equalling the pressure differential between head and sump than being a drain - but what happens if the oil level is above the level of the rear drain you going to get the same situation.

The way I see it is if the sump itself is vented then you will never have any issue as all the oil drains back from the head will be more than ample to keep the oil in the sump.

It might be an easier option then lifting the head as well if your enigne is back together.

Has anybody tryed venting the sump to atmoshpere/catch can to prevent the pressure build up within the crank.

My thoughts are that with sustained high rpm/load the crankcase is pressurising causing the oil not to drain back to the sump. The oil galleries are below the level of oil which means if the sump is pressurised there is no way for oil to drain back. This is why the mod to drain the back of the head via the welch plug on the rear will work as is it more to do with equalling the pressure differential between head and sump than being a drain - but what happens if the oil level is above the level of the rear drain you going to get the same situation.

The way I see it is if the sump itself is vented then you will never have any issue as all the oil drains back from the head will be more than ample to keep the oil in the sump.

It might be an easier option then lifting the head as well if your enigne is back together.

That's a good solution if blow by is a problem. But that's got zero to do with the fact that the head has insufficient oil return capacity for sustained high rpm. Venting the sump does nothing for that problem.

The oil return is best done to the LHS of the sump. Since the crank turns clockwise, that means the oil is returning into the partial vacuum created by the crank rotation. Hence the oil flows intro the sump. Oil level nothwithstanding.

:D cheers :(

my solution to oil dramas in a rb30det (gtr head) and stock bottome end is average oil (magnatec)

anything lighter and it blows by

magnatec is the shit for stock bottome ends

yea baby!!!!

just filler her up and extra two litres for circuit work!!!

cheap effective (buit overall stupid)

has anyone who has done this modification of restricting oil flow and lowering oil pressure to the cam journal bearings noticed increased wear?

the problem seems like its an oil return, not a supply problem. if you restrict the flowrate the cylinder head doesnt recieve enough cooling. also the pressure drops because of the restriction and you now have issues with maintaining the hydrodynamic lubrication of the journal bearings. this leads to increased mechanical contact between the bearing surfaces.

why not do as is already suggested and improve return oil flow? increasing oil gallery size and added external lines are perfectly fine.

Sk would have noted that already on the RB powered race cars he deals with, so clearly not a problem. I'm about to pull down my 25 that I had blocked the front supply off on so will know soon enough.

Clearly this is not just a return problem but a oversupply problem at high RPM as well, hence the restrictions.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • The average previous owner for these cars were basically S-chassis owners in the US. Teenagers or teenager-adjacent. I often tell people that neglect is easier to fix than something that was actively "repaired" by previous owners.
    • Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
×
×
  • Create New...